Cartridge retaining device



March 8, 1932. D. HODGE 1,848,129

CARTRIDGE RETAINING DEVICE Filed June 8, 1929 3 Sheets-Sheet 1 Dav/d Hodge attor e5 frwenfof March 8, 1932. D. HODGE 1,848,129

CARTRIDGE RETAINING DEVICE Filed June 8, 1929 s Sheets-Sheet 2 711/14 y a! T? fiwe zzzo f Dar/d Hodge f By ll pnes k E;

March 8, 1932. D. HODGE ,84

CARTRIDGE RETAINING DEVICE I Filed June 8, 1929 3 Sheets-Sheet 3 I M 97215 Dav/d H04 B5 Wp70e56 @Torney 6% a I Patented Mar. 8, 1932 UNETEE STATES hdded t earnest caries DAVID HODGE, OF CENTRALIA, ILLINOIS, ASSIGNOB TO SAFETY MINING COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION CARTRIDGE RETAINING DEVICE Application filed June 8, 1929, Serial No. 369,290, and in Great Britain October 16, 1928.

The present invention relates to an improved means for retaining a blasting charge in cartridge or other form within the drill hole wherein it is intended to be discharged. In present mine blasting practice, it is customary to provide 'a tamping behind the cartridge or other explosive medium for the purpose of holding the same to its Work. This tamping usually consists of coal particles and dust or other materials of a similar nature which are readily available in mines. Such material is packed into the drillhole behind the cartridge after the latter has been positioned and is then tamped to form a compact holding wad which serves to resist displacement of the blasting charge. some instances mechanical devices have been em ployed for this purpose. Such devices are usually referred to as mech'anicaldummies and consist of a metallic device adapted to be inserted in the drill hole and to be expanded therein so as to form a locked packing. The mechanical devices heretofore developed have not'been entirely satisfactory and it is therefore the aim of the present invention to provide an improved form of mechanical dummy.

It is an object of the invention to provide a mechanical device for the purpose described which is of such construction and design as to be capable of withstanding for long periods of time the severe conditions which exist in practical mine blasting operation.

It is a further object of the invention to generally improve the operating mechanism by which a device of this character may be readily inserted into and locked in position in the drill hole. 1

Other objects and advantages of the invention will appear in connection with the following description of the accompanying drawings wherein,

Figure 1 is a view in side elevation with portions in section illustrating one form of the present invention.

Figure 2 is a transverse section through an intermediate portion of Figure 1.

Figure 3 is a view in longitudinal section showing a modified form of the invention.

Figure 4 is a view in end elevation looking from the left in Figure 3. V

Figure 5 is atransverse section taken along the line 55 of Figure 3.

Figure 6 is a View in longitudinal section showing a still further modification of the invention.

Figure 7 is a transverse section taken along line 7.7 of Figure 6.

Figure 8 is a vlew in end elevation of the device shown in Figure 6.

Figure 9 is a transverse section takenalong line 99 of Figure 1.

Referring first to the form of the invention shown in Figures 1, 2, and 9, this device consists of a body portion 1 which is recessed intermediate its ends to form a pair of upstanding bosses 3 and 4 adjacent the respective ends of the body portion. These bosses are provided with aligned bores 5 and 6, the

former of which is provided with internal screw threads. An actuating spindle 7 is passed axially through the aligned bores, the same having threaded connection with the threads of bore 5 and being slidably received at its opposite end within the bore 6. This spindle isprovided with an operating head 8 which is suitably formed to receive any desired type of operating tool. A collar 10 is secured to the spindle 7 just inside of the upstanding boss 3 and positioned adjacent to collar 10 and rotatable with respect thereto is a thrust bearing ring 11. A portion 12 of the spindle is of reduced diameter for the purpose of receiving and guiding the plurality of anchoring elements to be hereafter described. The remote end of the spindle has secured thereto collar 13 which is slidably received within the bore 6 of the boss 4. Adjacent to the collar 13 is a loosely -mounted collar 13 which is provided with an upstanding lug 14 disposed within a slot 14 formed in the upper portion of the boss 4.

Arranged within the recessed portion of the body 1 and surrounding the reduced porti on 12 of the spindle is a plurality of movable anchoring elements 15. Each of these elements is formed with a pointed tip portion, a rounded base portion and an elongated and angularly disposed slot 16. The reduced 'tudinal movement ofthese elements.

portion 12 of the spindle is adapted to be passed through the slots 16 of the several anchoring elements and to thus confine the same against lateral movement while permitting them to have rocking movement by virtue of the elongated character and angular disposition of the slots. These anchoring elements are provided in suitable number to substantially fill the space between the thrust ring 11 and the lug 14 of the collar 13. Thus, the lug 14 bears against an anchoring element at one end of the series and the thrust ring 11 bears against a similar element at the opposite end of the series; The bottom wall of the recessed portion of the body is so formed as to provide a supporting surface for the curved bottoms of the several anchoring elements and to confine these elements to a purely rocking movement. The extremities of this supporting surface are defined by curved shoulders 18 and 19which engage the anchoring elements at the respectiveends of the series thereof and serve to prevent longi- The bottom surface of the anchoring elements are of irregular or eccentric form so that the rocking movement thereof is accompanied by a certain degree of transverse movement. This will be readily understood by reference to Figure 1 wherein the anchoring elements are shown in both full and dotted line positions corresponding to the twoextremesof movement thereof. when in the full line position the elements are disposed entirely within the confines of the body portion, whereas in the dotted line position thetips of the elements are projected a considerable distance beyond the surface of thebody portion. It will be noted that suitable teeth 2 may be provided on the body portion. These teeth preferably extend transversely across the bottom surface of the body portion and to some extent on each side thereof.

From the preceding description it will be understood that rotation of the spindle 7- is effective to produce a longitudinal movement thereof with respect to the body portion of the device. In view of the fact'that the anchoring elements are positively retained between the lug 14 and bearing ring 11 on the spindle it is apparent that the longitudinal movement of the spindle will affect a corresponding movement of the upper portions of the anchoring elements. By reason of the manner in which the lower'portions of the anchoring elements are supported and confined, it will be understood that the axial -movement of the spindle produces a pivoting action of the several elements, this action being permitted by the elongated and angularly disposed slots in the said elements. This pivotal movement is accompanied by a substantial transverse movement of the individual elements 1n the manner hereinabove set forth.

It will be observed that movement The modified form of the invention shown in Figures 8, 4, and 5 consist essentially of a pair of substantially semi-cylindrical toothed parts 3e and 35 which are adapted to be ex panded by means of a conical member 32 which is supported upon a threaded spindle 30. -The threaded portion 31 of the spindle receives a nut 82 which is arranged in abutting relation with the end of the conical member so that adjustmentof the nut serves to produce axial movement of the conical memher. In this constructionit is essential that the supporting spindle 30 be held against rotation with respect to the anchoring members 34; and 35 and for this purpose these members are provided with complemental rectangular slots 36 which are adapted to receive the rec-v tangular head 37 ofthe rod 30. For the purpose of normally holding the anchoring ele ments 34 and 35 in retracted position, there is provided a pair of transversely arranged headed bolts 38 and 39 which pass through the respective members. Intermediate each bolt head and the anchoring member with which it is associated there is positioned an expansible spring which serves to force the two anchor members toward each other. The openings through which these bolts are adapted to be inserted in the assembly of the device may be closed by suitable plug members 40.

A further modification of the invention is shown in Figures 6,7, and 8. In this form the two semi-cylindrical anchoring elements 55 and 56 are provided internally with substantially conical bores which are adapted to receive the conical expanding 'nuts- 53 and 54. These nuts are provided with reversely directed threads forcooperation with the.

right and left hand-threads formed on opposite ends of spindle 50. It will be understood that rotation of the spindle 50 may be eifected by the application of a suitable tool to the head 60 thereof and that such rotation serves to produce movement of the expanding nuts 53 and 54; toward or from each other, depende ing upon 'the direction of rotation v of the spindle, thus causing relative transverse of the anchoring members 55 and In the operation of this form of the invention it is essential that the nuts 53 and 54 be constrained against rotation with respect to the anchorlng members; and for this purpose I provide said nuts with friction gripplng or clutchlng surfacesin the form of rings 61 and 62 of any suitable friction producing material.

The anchoring members 55 and 56 are formed intermediate their ends with comple mental bearing portions 57 which serve to support the spindle 50 and maintain the same in proper alignment. Arranged on either side of this bearing portion 57 are collars 63 and 64 which are secured to the spindle in any suitable manner and between whichiand bearing portion 57 are interposed the thrust washers 55 and 56. The collars 63 and 64 serve to prevent axial movement of the spindle with respect to the anchoring members. It will also be noted that this form of the invention includes a suitable spring means for normally holding the anchoring members in retracted position, such means being substantially identical in form with that shown in Figure 5.

In the use of the present invention in connection with blasting by means of electrically energized cartridges or the like, it is necessary that some means be provided to accommodate the extension of a firing cable from the cartridge outwardly to the source of current. For this purpose I have shown in Figures 6, 7, and 8 a longitudinal groove 56 which is formed in the surface of the anchor member 56. By means of this construction a firing cable may be passed through the drill hole without in any way afi'ecting the necessary closing of the same by means of the present mechanical dummy. It will be noted that similar provision is made for the firing cable in the construction shown in Figures 1, 2 and 9 and it will be understood that the same expedient may be resorted to in connection with the modification shown in Figure 3.

It should be appreciated that the present invention is susceptible of some changes without departure from the scope thereof and for this reason it is intended that the invention be unrestricted otherwise than by the appended claims.

What I claim is:

1. In a device of the character described adapted to be positioned within a shot hole and to be anchored therein, a substantially cylindrical bodv portion recessed intermediate its ends to form upstanding bosses adjacent the respective ends thereof. said bosses being provided with aligned bores, a rod projecting through and having threaded engagement with one of said bores and having its end slid ably disposed within the other said bore and a plurality of anchor elements surrounding said rod and adapted to be moved to and from anchoring position by longitudinal movements of said rod.

2. A device substantially as set forth in claim 1 and wherein said body portion is provided with a plurality of integrally formed teeth. I

3. In a device of the character described adapted to be positioned within a shot hole and anchored therein, a substantially cylindrical body portion recessed intermediate its ends to form upstanding bosses adiacent the respective ends thereof, said bosses being provided with aligned bores, a rod projecting through and having threaded engagement with one of said bores and having its end slidably disposed within the other said bore and a plurality of anchor elements having rockable support on said body portion and adapted to be rocked to and from anchoring position by longitudinal movements of said rod.

4:. In a device of the character described adapted to be positioned within a shot hole and anchored therein, a substantially cylindrical body portion recessed intermediate its ends to form upstanding bosses adjacent the respective ends thereof, said bosses being provided with aligned bores, a rod projecting through and having threaded engagement with one of said bores and having its end slidably disposed within the other said bore and a series of anchor elements surrounding said rod, a pair of spaced abutments on said rod between which said elements are disposed and means for supporting said elements whereby longitudinal movements of said rod effect movement of said elements to and from anchoring position.

Signed at London, England, this 23rd day of May, 1929.

DAVID HODGE. 

